1. Field of the Invention
This invention relates to agricultural cultivators and more particularly, to a drag attachment and linkage for disks and similar cultivating implements, which drag attachment is adjustably manipulated by operation of one or more conventional fluid cylinders located on the disk to raise and lower a drag pipe, harrow or other ground-engaging agricultural implement connected to the drag attachment.
One of the problems associated with the use of conventional agricultural cultivators such as disks, harrows, chisel plows and like cultivators is the difficulty of operating the cultivators over terrain which is not level. This problem is intensified under circumstances where the farmer is attempting to level the ground and break up the larger clumps of dirt prior to planting. The levelling and seed bed preparation is typically undertaken using two tractors, one of which is used to disk the ground and the other to follow the disk tractor and pull a leveling board or other ground-engaging implement for smoothing the sod turned up by the disk blades. Other problems realized in this procedure are compacting of the ground by the second tractor and increased operating costs resulting from the requirement of using two tractors to achieve the desired goal. Since the preparation of seed beds can cost the farmer from 1% to 5% of the cost of his crop, the economical use of proper agricultural cultivating equipment is important in maximizing profits in the farming operation. Yet another problem arises due to the requirement of periodically raising the ground-engaging implement from contact with the ground for traversing roads and areas of the field which are not to be cultivated. Still another problem encountered in conventional implement raising and lowering equipment found on disks and cultivators is the high frequency of repair which is apparent due to damaging of the equipment by traversal of uneven terrain.
2. Description of the Prior Art
Many agricultural cultivators have been devised in the prior art to smooth the terrain and prepare seed beds for planting crops in farming operations. Cultivator frames which support a variety of ground-engaging implements, including harrow blades, disk blades and chisel plow blades, in non-exclusive particular, have been developed for the purpose of aerating, breaking up and smoothing the ground in order to provide a proper environment for the growth of new plants. Many of these cultivators include transport wheels which are pivotally mounted to the frame members in order to effect a selective lowering of the transport wheels to the ground and raising the cultivator frame and the ground-engaging elements, for transporting the cultivator over highways, roads and areas of the field which are not to be cultivated. Typical of the improvements in leveling mechanisms for cultivators such as disk harrows, is the "Leveling Mechanism for Rigid Frame Disk Harrows", disclosed in U.S. Pat. No. 2,767,538, dated Oct. 23, 1956, to Earl L. Scheidenhelm. This device includes an improved leveling mechanism wherein the tongue of the frame of the device which is attached to the towing vehicle and the supporting wheels of the frame are controlled together, so as to maintain the frame in a level attitude or at a desired angle with respect to the horizontal, together with depth control means operable to limit the lowering of the disks in both the disking and carrying positions. U.S. Pat. No. 4,428,435, dated Jan. 31, 1984, to Kevin L. Hubbard discloses an "Agricultural Implement with Hitch Control", which is designed to enable the implement to follow the ground contour by providing a floating hitch member. The device includes a linkage connected between a hitch member control mechanism and the cranked axle that serves as the wheeled carrying structure for the implement main frame. The linkage is arranged such that when the main frame is in a lowered or operating mode, a stop is spaced from the hitch member control so that the hitch member has a free pivotable movement about a transverse axis. Conversely, when the frame is raised to a transport or raised mode, the stop engages the hitch member control and renders the hitch member rigid with the frame. A "Sectional Implement Having Sequential Lifting and Lowering" is disclosed in U.S. Pat. No. 3,918,529, to Glen E. Frager, et al. The purpose of this implement is to provide a means by which the tool-supporting chassis of the implement may be rocked to the ground in such a manner as to engage one set of tools with the ground prior to engagement of another set of tools. In the case of a disk harrow, for example, it is preferred according to the disclosure, that the rear set of disks be grounded before the front set, thereby avoiding stress problems. The rear of a massive disk harrow is swung toward the ground first until the rear gangs are grounded, whereupon the front of the harrow is then swung downwardly about the fulcrum between the rear gangs and the ground in order to lower the front gangs. The process is reversed when the gangs are raised from the ground with the front of the harrow lifting first, followed by the rear. A special articulated tongue facilitates this rocking action during raising and lowering. U.S. Pat. No. 2,580,100, dated Dec. 25, 1951, to Gordon W. Johansen, et al, discloses an "Implement Raising and Locking Device", which is operative to raise an implement from a lowered working position to a raised inoperative position and in the latter position, to effectively lock the implement and its normally vertically swingable hitch unit against relative buckling in a vertical plane, so that the implement does not teeter when raised for turning in a field or for transportation from place to place. U.S. Pat. No. 3,225,839, dated Dec. 28, 1965, to William H. Petitt, discloses a "Mechanism for Adjusting Tool and Ground Support Relative to Supporting Frame" which is designed as a seed bed preparation device wherein a plurality of ground-engaging implements are pivotally supported on a wheel-transported frame. A plurality of ground-engaging elements such as a spring tube harrow, pulverizer wheels, a pegged tube harrow and a drag board may be pivoted in an agricultural frame by the mechanism disclosed in this patent. A rock shaft is pivoted in the frame and a pair of transport wheels depend from the rock shaft. Link means are provided for interconnecting the rock shaft and one or more of the ground-engaging implements and a hydraulic cylinder is employed to pivot the rock shaft, thus resulting in a longitudinal movement of the link means and simultaneous pivoting of the ground-engaging implements, so that as the transport wheels engage the ground, the ground-engaging elements are withdrawn from the ground and vice versa. U.S. Pat. No. 3,090,447, dated May 21, 1963, to Robert J. Hotchkiss, Jr., discloses a "Combination Disk Harrow and Tooth Drag Attachment". This patent discloses a cultivator attachment in which the draw bars of the attachment are pivotally connected to a wheel-carrying element of the harrow, the pivotal connection permitting both horizontal and vertical movement of the attachment relative to the harrow.
One of the problems associated with cultivators having retractible or pivoting ground-engaging members such as the mechanisms disclosed in U.S. Pat. Nos. 3,225,839 and 3,090,447 described above, is the lack of sufficient range of lifting motion to prevent damage during traversal of uneven terrain. For example, if the ground-engaging implements are not lifted sufficiently high by operation of the lifting mechanism to prevent damage due to contact with stumps, logs or uneven terrain, costly repairs may be necessary. Another problem is lack of a built-in shock absorbing feature to prevent damage to the linkage systems resulting from contact with an unyielding object while the ground-engaging members are in the lowered configuration.
It is an object of this invention to provide a new and improved drag attachment for agricultural cultivators which requires minimum maintenance and is capable of traversing uneven ground without damage to the ground-engaging attachment elements or implements.
Another object of this invention is to provide a drag attachment and linkage for a disk or agricultural cultivator which is simple in design, easy to operate and utilizes the conventional transport wheels and hydraulic cylinder system provided on the disk or cultivator for operation.
Still another object of this invention is to provide a new and improved drag attachment for a disk or agricultural cultivator which incorporates a shock absorbing feature and is characterized by at least one drive arm connected to the conventional wheel shaft used to raise and lower the transport wheels, a pair of connecting links pivotally attached to the drive arm and to one end of a connecting rod, which connecting rod is in turn adjustably pivoted to a pivot arm rigidly carrying a lift frame which supports a drag pipe having pipe extenders telescoped therein.
Yet another object of the invention is to provide an adjustable support or linkage attachment for ground-engaging implements or components in a disk or agricultural cultivator, which attachment serves to strengthen the disk or cultivator frame and cooperates with the transport wheel raising and lowering mechanism to raise the ground-engaging implements when the transfer wheels are lowered or deployed on the ground and vice-versa, in an optimum range of motion.
A still further object of this invention is to provide a new and improved drag attachment or linkage system for a disk or agricultural cultivator, which attachment includes a pair of drive arms fixed to the pivotable conventional wheel shaft of a conventional disk, where the wheel shaft is designed to raise and lower the disk transport wheels, a set of double pivot links connecting each of the drive arms to one end of a pair of connecting rods adjustably attached to a clevis mount fixed to a pivot arm which is also pivoted to the frame of the disk at each end, with a pair of frame arms fixed to the pivot arm and extending downwardly to support a drag pipe, harrow or other leveling device, which leveling device can be quickly raised and lowered by pivoting the wheel shaft while raising and lowering the transport wheels.